CAD and Angina

Question 1

What factors affect the cardiac workload, and increases cardiac oxygen demand?

Answer 1

Increased heart rate
Increase force of contractility
Increased pre load
Increased afterload

Question 2

What factor decreases cardiac oxygen supply?

Answer 2

Decreased coronary blood flow

Question 3

What are the first line anti- anginal drugs

Answer 3

Organic nitrates- Nitroglycerin, isorbide mononitrate
beta blockers, atenolol, bisoprolol, carvedilol, metoprolol
Calcium channel blockers, Dilitiazem, verapamil, Amlodipine, Felodipine, Nicardipine
HCN4 Ion channel blocker, Ivabradine

Question 4

Which medication is commonly used as a vasodilator in the treatment of variant angina?
a) Isosorbide dinitrate
b) Diltiazem
c) Nitroglycerin
d) Verapamil

Answer 4

Answer: c) Nitroglycerin

Question 5

Which medication class is commonly used in the management of stable angina by reducing myocardial oxygen demand through negative inotropic and chronotropic effects?
Answer:
a) Nitrates
b) Beta-blockers
c) Calcium channel blockers
d) Angiotensin-converting enzyme (ACE) inhibitors

Answer 5

b) Beta-blockers

Question 6

Which medication is a potent vasodilator that primarily acts on arterial smooth muscle and is commonly used in the treatment of stable angina?
a) Isosorbide mononitrate
b) Ranolazine
c) Amlodipine
d) Verapamil

Answer 6

Answer: c) Amlodipine

Question 7

How do calcium channel blockers exert their antianginal effects?

Answer 7

Calcium channel blockers inhibit the influx of calcium ions into vascular smooth muscle cells and myocardial cells, leading to vasodilation of coronary and peripheral arteries, decreased myocardial contractility, and reduced myocardial oxygen demand.

Question 8

Explain the concept of preload reduction in the management of angina.

Answer 8

Preload reduction refers to the decrease in ventricular filling pressure and volume, which reduces the workload on the heart during diastole. Medications such as nitrates and diuretics can reduce preload by promoting venous dilation and decreasing blood volume, respectively, thereby reducing myocardial oxygen demand.

Question 9

How do beta-blockers exert their antianginal effects?

Answer 9

Beta-blockers primarily work by blocking beta-adrenergic receptors in the heart, leading to a reduction in heart rate, myocardial contractility, and cardiac output. By decreasing myocardial oxygen demand and improving coronary blood flow, beta-blockers are effective in the management of angina.

Question 10

MOA of Organic nitrates

Answer 10

Organic nitrates are pro-drugs and are converted into nitric oxide (NO) in vascular
smooth muscle cells (VSMCs). NO then activates guanylate cyclase, which converts GTP (guanosine triphosphate)
into cyclic GMP (cyclic guanosine monophosphate). Cyclic GMP then activates protein kinase G (PKG), which
ultimately causes the VSMCs in blood vessels to relax and induce vasodilation.

Question 11

3 function of GTNs

Answer 11

Works on collateral coronary arteries–> vasodilation– redistribute and increase blood flow–> ischemic cardiac tissue.
Causes vasodilation of veins and arterioles, to cause a decrease in venous pressure and decrease in TPR(artery) then decrease preload and afterload–> decreasing cardiac workload and cardiac o2 demand.

Question 12

Contraindications of GTN

Answer 12

Low SBP, Increased cranial pressure, Patients on PDE5 (viagra)

Question 13

contraindication of CCB

Answer 13

Patients with Heart Failure
Patients on β-Blockers: AV Heart Block

Question 14

MOA of CCB

Answer 14

1.
Arterioles+
(VSMCs)
VSMCs decrease ca,
Relax Vasodilation ↓TPR ↓MAP
2. Heart–> decrease Ca –> decrease HR, and contractile force–> increase period of diastole and increase in cornary artery opening time–> increase blood flow to ischaemic tissue
Decrease cardiac workload and decrease cardiac o2 demand.

Question 15

Side effects of CCB

Answer 15

1). Hypotension → Dizziness
2). Reflex Tachycardia (↑HR): Due to Aortic Arch and Carotid Sinus Baroreceptors detecting a decrease in blood pressure.
3). Headache
4). Flushing
5). Constipation: Due to decreased contraction of smooth muscle in the gastrointestinal system. Therefore, decreases digestion.
6). Peripheral Oedema: Due to Dilation of arterioles & No Dilation of Venules/Veins → Build-up of blood in capillaries → ↑
Hydrostatic Pressure in Capillaries → Water leaks into the interstitial compartment of the tissue.

Question 16

side effect of beta blockers

Answer 16

1). Hypotension → Dizziness and Fainting
2). Bradycardia
3). Atrioventricular (AV) Heart Block: This is where the electrical signal is blocked from the AV node to the Ventricles.
4). Fatigue
5)Bronchoconstriction: May block β2-adrenoreceptors in the airways
6). Hypoglycemia: May block β2- adrenoreceptors in the liver → inhibit glycogenolysis.
7). Cold Extremities (i.e. Hands and Feet)
8). Impotence

Question 17

Side effects of GTN

Answer 17

Develop Tolerance (body no longer respond to organic nitrates): Due to repeated or continuous exposure to high doses of
organic nitrates. Solution: Use low doses and stop treatment for 8-12 hours daily at night when the patient is usually inactive.
2). Orthostatic (Postural) Hypotension when standing.
3). Reflex Tachycardia: Due to Carotid Sinus & Aortic Arch Baroreceptors detecting a decrease in blood pressure.
4). Dizziness → Syncope (i.e. Fainting)
5). Migraine-Like Headaches: Due to dilation of meningeal artery.

Question 18

MOA of ivabradine

Answer 18

HCN4 Channel Blocker- blocks the HCN4 ion channel in the Sino-Atrial (SA) node of the heart.

Question 19

How it functions: ivabradine

Answer 19

Heart SA node–> decrease in generation of pacemaker current–> decrease rate of SA node depolarising–> decrease HR–> decrease cardiac workload and decrease o2 demand.
ALso increases period of diastole –> increase coronary artery opening

Question 20

Side effects of Ivabradine

Answer 20

Luminous Phenomena (Enhanced Vision Brightness): Due to blocking HCN ion channels in the retina as well.
Bradycardia (Decreased Heart Rate; <60 beats/min)
Atrioventricular (AV) Heart Block: This is where the electrical signal is blocked from the AV node to the Ventricles.
Blurred Vision
Headaches
Dizziness
Hypotension
Fatigue

Question 21

Contraindications of ivabradine

Answer 21

1). Sick Sinus Syndrome: Due to Sinus Node Defects
2). Patients on Ca2+ Channel Blockers (i.e. Verapamil & Diltiazem) = AV Heart Block
3)Patients on CYP3A4 inhibitors, Azole Antifungals (Ketocanozole), Macrolide Antibiotics, Anti-Retrovirals

Question 22

Contraindications of Beta blockers

Answer 22

Asthma
Diabetes
Patient on Calcium Channel Blockers